We present Surrogate Avatar, an adaptive telepresence method that enhances user mobility and situated co-presence in symmetric avatar-mediated communication. The system enables a remote user’s avatar to autonomously position itself in socially and environmentally appropriate locations within the local user’s space—based on spatial affordances, interactional norms, and environmental constraints—supporting fluid interaction without requiring a shared environmental context. Through a formative study, we derived key adaptation objectives and implemented them using a distributed optimization framework based on the AUIT system. The framework distributes adaptation tasks across server and client to balance responsiveness and computational efficiency. A user study involving both stationary and nomadic scenarios demonstrated consistently high usability and presence, with some limitations observed under walking conditions. An additional exploratory field study in a semi-structured public setting demonstrated the system’s viability beyond controlled lab conditions. These findings motivate future designs of mobile telepresence systems that dynamically adapt to spatial and conversational context while mitigating misunderstandings that can arise from asymmetric environmental awareness and supporting privacy-sensitive interaction.

Research has enabled virtual reality (VR) users to interact with the physical world by blending the physical world view into the virtual environment. However, current solutions are designed for specific use cases and hence are not capable of covering users’ varying needs for accessing information about the physical world. This work presents RealityLens, a user interface that allows users to peep into the physical world in VR with the reality lenses they deployed for their needs. For this purpose, we first conducted a preliminary study with experienced VR users to identify users’ needs for interacting with the physical world, which led to a set of features for customizing the scale, placement, and activation method of a reality lens. We evaluated the design in a user study (n=12) and collected the feedback of participants engaged in two VR applications while encountering a range of interventions from the physical world. The results show that users’ VR presence tends to be better preserved when interacting with the physical world with the support of the RealityLens interface.

This work presents Slice of Light, a visualization design created to enhance transparency and integrative transition between realities of Head-Mounted Display (HMD) users sharing the same physical environment. Targeted at reality-guests, Slice of Light's design enables guests to view other HMD users' interactions contextualized in their own virtual environments while allowing the guests to navigate among these virtual environments. In this paper, we detail our visualization design and the implementation. We demonstrate Slice of Light with a block-world construction scenario that involves a multi-HMD-user environment. VR developer and HCI expert participants were recruited to evaluate the scenario, and responded positively to Slice of Light. We discuss their feedback, our design insights, and the limitations of this work.

We present HMD Light, a proof-of-concept Head-Mounted Display (HMD) implementation that reveals the Virtual Reality (VR) user's experience in the physical environment to facilitate communication between VR and external users in a mobile VR context. While previous work externalized the VR user's experience through an on-HMD display, HMD Light places the display into the physical environment to enable larger display and interaction area. This work explores the interaction design space of HMD Light and presents four applications to demonstrate its versatility. Our exploratory user study observed participant pairs experience applications with HMD Light and evaluated usability, accessibility and social presence between users. From the results, we distill design insights for HMD Light and asymmetric VR collaboration.

This work presents HapticSphere, a wearable spherical surface enabled by bridging a finger and the head-mounted display (HMD) with a passive string. Users perceive a physical support on a finger attached to a string, when extending their arm and reaching out to the string's maximum extension. This physical support assists users in precise touch interaction in the context of stationary and walking virtual or mixed-reality experiences. We propose three methods of attachment of the haptic string (directly on the head or on the body), and illustrate a novel single-step calibration algorithm that supports these configurations by estimating a grand haptic sphere, once a head-coordinated touch interaction is established. Two user studies were conducted to validate our approach and to compare the touch performance with physical support in sitting and walking conditions in the context of mobile mixed-reality scenarios. The results show that, in the walking condition, touch interaction with physical support significantly outperformed the visual-only condition.

Currently, "walkable" virtual reality (VR) is achieved by dedicating a room-sized space for VR activities, which is not shared with non-HMD users engaged in their own activities. To achieve the goal of allowing shared use of space for all users while overcoming the obvious difficulty of integrating use with those immersed in a VR experience, we present ShareSpace, a system that allows external users to communicate their needs for physical space to those wearing an HMD and immersed in their VR experience. ShareSpace works by allowing external users to place "shields" in the virtual environment by using a set of physical shield tools. A pad visualizer helps this process by allowing external users to examine the arrangement of virtual shields. We also discuss interaction techniques that minimize the interference between the respective activities of the HMD wearers and the other users of the same physical space. To evaluate our design, a user study was conducted to collect user feedback from participants in four trial scenarios. The results indicate that our ShareSpace system allows users to perform their respective activities with improved engagement and safety. In addition, this study shows that while the HMD users did perceive a considerable degree of interference due to the internal visual indications from the ShareSpace system, they were still more engaged in their VR experience than when interrupted by direct external physical interference initiated by external users.